In recent years, the design of modern offices has changed dramatically. Current office design most often utilizes free standing work modules which can be readily modified to meet the changing demands of the business rather than the traditional arrangement having private offices with permanent partitions and a large open work space for those workers who do not require a quiet, private office. This change in office design has coincided with current recognition of the need for energy conservation. Therefore, rather than provide high levels of illumination from ceiling fixtures, the current trend is to provide low level room illumination and individually controlled high level task lighting for desks or work stations.
Commercially available modular work stations are designed such that the work surface or "desk" top is built into or attached to the free standing partitions that define the individual work stations. It is common with these units to also employ book shelves or storage units above the desk area. Lighting fixtures, usually strip fluorescents, are installed under these storage units to provide high intensity task lighting for the work surface.
For optimal working conditions, the task lighting must produce glare-free, even lighting at the work surface. Light from the fixture must also be prevented from shining into the worker's eyes.
A number of lighting fixtures have been proposed to accomplish these ends such as U.S. Pat. Nos. 4,054,793 (Shemitz), 4,161,767 (Benasutti), and 4,383,289 (Lewin). U.S. Pat. Nos. 2,240,179 and 2,560,281 (Doane) while not directly concerned with task lighting, disclose fixtures for uniformly illuminating the area beneath the fixtures. However, none of these fixtures are completely satisfactory. Those that use diffusers between the light source and the work surface, of necessity, lose a proportion of the light energy in the diffuser. Those that use a reflector behind the light source to direct the light toward the work surface either do not provide even illumination or result in a lighting pattern that is fixed and may not be suitable for varying tasks that might be performed on the work surface.
It is therefore the object of this invention to provide a light fixture that is highly efficient in directing light from the light source to a work surface in a very even, glare-free manner. Further, the fixture is worker adjustable to allow variation of the light pattern over a broad range to accommodate lighting requirements of a wide range of tasks.